IGS电离层图内插区域电离层电子含量精度分析

Analysis the Accuracy of Regional Ionospheric Electron Content Obtained Through Interpolating the IGS Maps

本文以重庆CORS网2007年第247天5个基准站观测数据为例,首先采用平滑伪距观测值解算各个基准站上空的VTEC值,然后将其中的4个测站穿刺点处的VTEC值采用克里金插值法内插YUBE站上空的穿刺点处的VTEC,发现克里金插值法内插的电离层穿刺点的VTEC值精度是可靠的,且比高精度的广义三角级数函数模型计算精度更高。再利用IGS电离层图,采用电离层穿刺点周围4个电离层图点和包含电离层穿刺点的所有格网点内插BANA站整点时刻的电离层VTEC值,经比较发现两者的内插精度基本一致。最后,利用包含电离层穿刺点的所有IGS电离层图点内插重庆CORS网5个基准站上空的整点时刻电离层VTEC值,经分析发现由IGS电离层图内插的5个基准站上空的VTEC值均比采用平滑伪距观测值解算的VTEC值偏大,约3.454TECU,且插值结果精度低于广义三角级数函数模型计算精度。

It takes the observation data for 247 th day in 2007 of five reference stations in Chongqing CORS network of as example.Firstly,it is obtained the vertical total electron contents（VTEC）with GPS smoothed pseudo-range observations of the five base stations.Then,the VTEC of the four stations are interpolated another station VTEC adopting Kriging interpolation,compared the interpolation results to the modeling results of generalized trigonometric series function to VTEC obtained from GPS observation data,it is found that the accuracy of Kriging interpolation is higher than the generalized trigonometric series function model simulation.And then,the IGS ionospheric map are interpolated the VTEC of BANA at integral time adopting four grid points around ionospheric pierce point and all grid points around ionospheric pierce points,compared the interpolation results,it is found that the interpolation accuracy of the two is the same.Finally,adopting all grid points around ionospheric pierce points to interpolate the VTEC of Chongqing CORS network five reference stations at integral time,compared the interpolation results to the VTEC of GPS pseudorange observation,it is found that the interpolated results is higher,about 3.454 TECU,compared to the generalized trigonometric series function model simulation,the accuracy of interpolation results is lower.